OK.....in an effort to make things a bit easier, I added two more buttons for youtube embedding. Unfortunately I can't have one button work with several different codes ( I tried it ), so new buttons it is.

If your YT url starts with http:// https:// or just www there's a button for each one of those cases now.

Obviously you have to know which to use so this may do more harm than good, but enough people struggle with this to warrant making it easier. Apologies for the awkward functionality.